1. Field of the Invention
The present invention relates to a wire harness for a vehicle seat disposed in the vehicle seat.
2. Description of the Related Art
A vehicle seat is provided with an electric seat apparatus which adjusts a position of a seat cushion in a longitudinal direction and a vertical direction in accordance with a posture of a passenger or for reclining a seat back, or with an air bag unit apparatus for inflating an air bag between the passenger and a side door. In the vehicle seat having such an apparatus, a wire harness is disposed.
A proposed wire harness structure for such a vehicle seat will be explained using FIG. 1. In FIG. 1, a vehicle seat 1 includes a seat skeleton 2 on the side of a seat cushion and a seat skeleton 3 on the side of a seat back. The seat skeleton 2 on the side of the seat cushion is provided with switches such as a main switch SW1, a lamber support switch SW2 and a buckle switch SW3, and first to fourth motors M1 to M4 which are driving sources for adjusting a position of the seat cushion and an inclined position of the seat back. The seat skeleton 3 on the side of the seat back is provided with a fifth motor M5 which is a driving source for adjusting a back-abutting position of the seat back and an air bag unit 4.
Wire harnesses 5 are disposed in the vehicle seat 1 so that the motors M1 to M5 receive driving signals and electric power supply based on operation signals from the switches SW1 to SW3, the switches SW1 to SW3 receive output the operation signals for controlling the motors M1 to M5 or receive the electric power supply, and the air bag unit 4 output the inflating signal or receive the electric power supply.
The wire harness 5 comprises electric wires having substantially circular cross section covering insulative material bound around an outer periphery of conductive material for example, and the wire harnesses disposed between the same routes are covered with exterior material (not shown) such as corrugate tube, VO tube or the like. Each the wire harness 5 covered with the exterior material is fixed to the seat skeletons 2 and 3 by a clamp member 6 or fixed to a spring 8 of the seat cushion by a tie band member 7. That is, the wire harnesses 5 prevent interference damage to the utmost with respect to the vehicle seat 1 by covering the wire harnesses 5 with the exterior material, and keep appropriate disposing state by fixing the wire harnesses 5 to the seat skeletons 2 and 3.
However, in the case of the conventional wire harness 5, since most of portions of the wire harnesses 5 are covered with the exterior material to prevent the interference damage to the utmost with respect to the vehicle seat 1 as described above, this inhibits automatization for producing the wire harness 5.
Further, since the wire harnesses 5 are assembled into the vehicle seat 1 in such a manner than portions of the wire harnesses are fixed using the clamp member 6 or the tie band member 7, the number of fixing portions is great, the two kinds of fixing members, i.e., the clamp member 6 or the tie band member 7 must be used, and there is a problem that the assembling performance is inferior.
To solve such problems, the present applicant proposed a wire harness for a vehicle seat comprising a flat-like circuit branch and a flat circuit body whose one end is connected to the circuit branch and whose other end is connected to an electric part. In this wire harness for the vehicle seat, the circuit branch and the peripheral flat circuit body are supported by a protection seat, and the wire harness can be fixed to the vehicle seat through the protection seat. With this arrangement, it is possible to prevent the damage caused by interference with respect to the vehicle seat, to enhance the automatization for producing the wire harness, and to enhance the assembling operability of the harness to the vehicle seat.
Meanwhile, required function is varied depending upon the specification or grade of the vehicle seat. In the wire harness for the vehicle seat, it is conceived that different circuit branches are prepared for different specifications or grades of the vehicle seat so as to meat the specification or grade of the vehicle seat. However, if different circuit branches are prepared for different specifications or grades of the vehicle seat, there is a problem that the number of parts is increased. Further, it is conceived that an electronic circuit of the circuit branch is set to the highest specification or highest grade. However, if the circuit branch has the highest function, there is a problem that the circuit branch is increased in size and the cost is increased.
It is an object of the present invention to provide a wire harness for a vehicle seat in which the number of parts of a circuit branch is reduced to the minimum level for standardization, the disposing space of the circuit branch is reduced to the minimum level, the cost is low, and the wire harness can meet a specification or grade of the vehicle seat.
According to a first aspect of the present invention, there is provided a wire harness for a vehicle seat disposed in the vehicle seat for electrically connecting electric parts to one another, comprising flat circuit branch, and a flat circuit body whose one end is connected to the circuit branch and whose other end is connected to the electric parts, wherein the circuit branch comprises a sheet of branch seat or a plurality of sheets of branch seats selectively laminated on one another so that an electronic circuit corresponding to specification or grade of the vehicle seat can be constituted.
With this wire harness for a vehicle seat, the branch seat of the circuit branch is selected in accordance with the specification or grade of the vehicle seat. If the number of the selected branch seat is one, this one branch seat is used as the circuit branch, and if two or more branch seats are selected, these are laminated and used. As the number of parts of the circuit branch, the branch seat having the basic function and one or more addition seats each having the additional function suffice, and only necessary branch seat of these branch seats is used.
According to a second aspect of the invention, the branch seat is provided with a notch for exposing a conductive portion of another branch seat to be laminated.
With this wire harness for a vehicle seat, in addition to the effect of the first aspect, the plurality of branch seats are laminated on one another, and even if a conductive portion of the branch seat exists on the superposed surface, the flat circuit body can electrically be connected to the conductive portion of the desired branch seat by the-notch.
According to a third aspect of the invention, the branch seat has a memory and an electronic control unit for controlling using contents of the memory, and the electronic control unit is constituted by a flat circuit.
With this wire harness for a vehicle seat, in addition to the effect of the first or second aspect, one having the memory and the electronic control unit can be added as the branch seat.